TABLE 1.
Clinicopathologic Characteristics of Patients with T1-T2 Node-Negative Invasive Breast Cancer Treated by Mastectomy Without PMRT
| No PMRT n = 657 | |
|---|---|
|
| |
| Age, years | 49 (24–89) |
|
| |
| Histology | |
| Ductal | 566 (86%) |
| Lobular or mixed | 90 (14%) |
| Other | 1 (0.2%) |
|
| |
| Pathologic tumor size, cm | 1.4 (< 0.1–5.0) |
|
| |
| Associated DCIS | |
| < 25% | 404 (61%) |
| > 25% | 245 (37%) |
| Unknown | 8 (1%) |
|
| |
| Grade | |
| Low | 31 (5%) |
| Intermediate | 326 (50%) |
| High | 266 (40%) |
| Unknown | 34 (5%) |
|
| |
| Receptor status | |
| ER+/HER2– | 438 (67%) |
| ER+/HER2+ | 75 (11%) |
| ER–/HER2+ | 48 (7%) |
| ER–/HER2– | 70 (11%) |
| Unknown* | 26 (4%) |
|
| |
| Lymphovascular invasion | 232 (35%) |
|
| |
| Multifocal/multicentric | 447 (68%) |
|
| |
| Tumor location | |
| Medial or central | 226 (34%) |
| Lateral | 431 (66%) |
|
| |
| # of risk factors | |
| 1 | 183 (28%) |
| 2 | 265 (40%) |
| 3 | 143 (22%) |
| 4 | 28 (4%) |
| 5 | 4 (1%) |
| Unknown** | 34 (5%) |
Data reported as median (range) or n (%)
*
Cases with insufficient sample to test ER and/or HER2
**
Those with unknown nuclear grade excluded from risk factor analysis
Abbreviations: PMRT, postmastectomy radiotherapy; DCIS, ductal carcinoma in situ; ER, estrogen receptor; HER2, human epidermal growth factor 2